Electromagnet device



Sept. 11, 1962 H. KUHNKE 3,

ELECTROMAGNET DEVICE Filed June 1, 1959 2 heets-Sheet 1 1m 9 1. g 5 /@F a @[2722 6 9 z 75 a E 4 Q Inventor Hal/muff; Hu/mke United States PatentC 3,654,028 LEQTRGll EAGNET DEVKCE Hellmuth Kuhn-ire, Eutinerstrasse 25, Malente, Halstein, Germany Filed June 1, 1959*, Ser. No. 817,229 Claims priority, application Germany .l'nne 6, 1958 11 Claims. (61. 317- 198) In the electro-magnetic actuation of switching members, for example relay contacts, by means of mechanical levers or the like, a problem arises due to the fact that the attraction power of the magnet decreases substantially, owing to the leakage field, when the air gap increases. For this reason, electro-magnetic actuation is limited to relatively small movements of the armature, unless one is prepared to use extraordinarily large magnets which absorb correspondingly large amounts of energy. To enable, in spite of this, a large displacement to be produced, lever transmissions are interposed in known constructions, which convert a small armature travel of the electromagnet into a large operating movement. If one is not prepared to resort to complicated mechanical auxiliary means, the use of lever devices for the armature and for the actuation members will produce a rotary motion which, in many cases, is undesirable, in particular for the armature. A magnet of which the armature effects a purely translational movement possesses advantages as compared with a magnet having a tilting armature, because the leakage flux is smaller than that of a tilting armature of equal mean armature travel.

The invention provides an electromagnet arrangement which incorporates an armature which effects a purely translational movement, wherein a very small movement of the armature in the direction of its attraction by the magnet is converted, in a simple manner, into a larger movement in a direction of actuation which is perpendicular to the attraction direction. The invention consists in that the attraction movement of the armature is converted by means of rolling members, in particular balls, which roll on surfaces extending obliquely to the attraction movement of the armature, into a translational movement in a direction substantially perpendicular to the attraction movement of the armature. The translational motion is used for actuating electrical or mechanical switching devices. The conversion arrangement for increasing the armature motion produces only small friction, occupies only a small space, and enables the armature having a purely translational motion to be constructed with a large surface area. The construction is particularly simple if the armature itself, or a part fixed thereto, runs on the rollers in such a manner that it effects, simultaneously with the attraction movement a larger movement perpendicularly thereto.

It is already known in the case of rotary magnets to dispose the armature of an electro-magnet on a sloping surface, but in that case it is a matter of converting the translational movement of the armature into a rotary motion.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawing, in which:

FIGURE 1 is a side view of one embodiment of an electromagnet according to the invention,

FIGURE 2 is a plan view of FIGURE 1,

FIGURE 3 is a view in the direction of the arrow A in FIGURE 1,

FIGURE 4 is a fragmentary section along the line B--C of FIGURE 2,

FIGURE 5 is a fragmentary section along the line D-E of FIGURE 2,

FIGURES 6 and 7 are sections of two other embodiments.

Referring to FIGURES 1 to 5 of the drawings, the electromagnet consists of an E-shaped iron core 1 of iron laminations. On its central limb is a winding 2. Between the central limb and the two outer limbs there is, in each case, a relatively large air gap 3. The movable armature 4 is situated opposite to the pole faces of the magnet and a very small distance therefrom. Since the distance between the armature and the pole faces of the E-shaped magnet is very small, the lines of force extend mainly through the armature and not through the air gaps 3 since these are substantially larger. The armature 4 is mounted at three points, which are preferably symmetrically distributed, on balls 15, 16, 17 running on inclined surfaces which are conveniently formed as grooves with inclined bottom surfaces in the steel parts 5, 6, 7, 8, 9, 10. These steel parts are screwed to rails of nonmagnetic material, for example brass, which are designated in the drawing by the reference numerals 11, 12, 13, 14, 19 and 20 and which extend parallel to the upper edge of the magnet and to the side faces of the armature. These rails not only provide a fixing for the steel parts but also removes them as far as possible out of the zone of magnetic flux of the electromagnet. The parts 5-10 are provided with inclined grooves in which run the balls 15, 16 and 17, as can be seen in particular from the sectional FIGURES 4 and 5. By means of springs 18a which are tensioned obliquely to the vertical and extend between the armature and the base plate 18, the armature is urged into its normal position towards the left (FIGURE 5) in which it is raised to its highest position above the pole faces of the magnet. The springs 18 also hold the armature in position on the ball bearings 15, 16, 17. End position stops are provided, by the ends of the grooves in which the balls run. However, additional stops may also be provided if desired.

When the electromagnet is excited, the armature is magnetically attracted towards the electromagnet and, as a consequence of the inclined surfaces and ball bearing arrangement, this attraction produces a movement in the direction of the attraction as well as a substantially increased translational movement perpendicularly thereto towards the right. This increased translational movement perpendicular to the attraction direction may then be used for actuating various devices, for example for actuating contacts of relays or contactors, or may be used for producing a mechanical motion of various devices, for example in calculating machines. As is clearly shown in the drawing, the conversion ratio may be altered by suitably altering the inclination of the grooves in which the balls run, and the conversion ratio may be rather large. The air gap through which the attraction movement of the armature extends is very small, and since a large surface of the armature is constantly disposed opposite the electromagnet, the leakage flux is moreover very small. It should be noted that the armature 4 extends beyond the surface of the electromagnet by a distance corresponding to its translational movement perpendicular to the attraction direction. Moreover, by providing the sloping bottoms of the grooves with a suitable curvature, a different conversion ratio can be obtained for different positions of the armature.

The specific embodiment shows, in its simplest form, the actuation of a contact by means of the magnet arrangement. For this purpose an insulation member 21 is fixed to the end of the two rails 19 and 20 and a contact 22 is mounted on this insulation memiber. Opposite contact 22 is positioned a contact 23 which is fixed to a spring 24. By actuating the electromagnet the two contacts are urged into a mutually abutting relationship. The additional movement of the armature in the attraction direction of the magnet has a favourable effect because thereby a slight wiping movement of the contact surfaces is produced which removes dirt from the contact surfaces.

In place of the springs 18a, the armature guide may be guided in other ways, for example by means of rollers or balls pressing from above and preferably mounted in a resilient manner.

The specific embodiment shown corresponds to a very simplified form of the invention and is intended to describe its mode of operation. Various constructional embodiments may be devised which enable a plurality of contacts to be actuated, in particular weak current contacts of relays, and which also enable mechanical switching members to be actuated. Instead of the balls, other rolling members may be used, for example it is possible to run the armature on two roller members or needles. Similarly, the sloping surfaces may be replaced by slots in fiat plates the slots having obliquely extending edges on which balls run and sink to a greater or lesser extent in accordance with the edge spacing.

FIGURES 6 and 7 show particularly simple embodiments of the invention which are intended, in particular, for use with relays. The guide members for the balls are here disposed in the magnetic circuit, which is quite feasible in practice.

FIGURE 6 shows an embodiment in which the whole moving mechanism of the armature is disposed within the coil 25. The coil has a bent iron core 26 of strip iron, the iron core being closed inside the coil with the exception of one air gap 27. The movable armature 28 is mounted and arranged to slide inside the coil opposite the air gap. The sloping surfaces on which the balls run are in this case formed directly in the armature and in the opposing limbs of the fixed core. Three running grooves are again provided. The pair of grooves 29 and 30 provided in the centre line of the core and the armature are shown in section in FIGURE 6. A ball 31 runs between these grooves. The two other pairs of grooves disposed at the sides of the section line are shown dotted at 32 and 33. The associated ball is shown at 34. A leaf spring 35 is provided inside the coil member and guides the armature on the side remote from the balls. The two ends of this spring which are adjacent the coil member engage in small recesses (not shown) in the coil member, and therefore only a sliding motion occurs between the armature and the spring. A spring 37 connected between the coil member and the armature restores the armature into its normal position.

FIGURE 7 shows another embodiment in which the mechanism for moving the armature is similar to that of FIGURE 6 but is disposed outside the coil instead of within it. It is shown in its application to a relay. The coil member 38 has a bent core 39, made of strip iron, passing therethrough. The movable armature is designated by 40. The grooves for the balls are again provided, as in FIGURE 6, in the armature itself and in the oppositely disposed limbs of the core. The guide arrangement for the armature is provided by two leaf springs 41 and 4-2 which give it a slight initial bias in the direction towards the limbs of the core and towards its unexcited end position. On exciting the core 38, the armature moves towards the core and simultaneously upwards due to the conversion of the movement. In doing so it thrusts against the upper obliquely bent end of a spring 43 of the contact set of the relay. By this means contact 44 is closed and the other springs 45, 46, 47 of the relay are also actuated for contact closure. The relay springs are fixed in the base plate 48 which carries the iron core 39 and the magnet coil 38.

I claim:

1. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising rolling members between said coil and said armature, means including surfaces oblique to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movet ment of said armature is converted into a non-rotary translatory movement outwardly away from said coil.

2. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising rolling members between said coil and said armature, means including surfaces oblique to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a nonrotary translatory movement on said rolling members on energisation of said coil whereby the armature carries out simultaneously an attraction movement towards said coil and a rectilinear movement at right angles to said attraction movement upon energisation of said coil.

3. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising rolling members between said coil and said armature, means including curved surfaces located obliquely to the attraction movement of said armature and in contact with said rolling members, said armature sliding in non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non rotary translatory movement.

4. An electromagnet having an exciting magnet surrounding by an energising coil and an armature movable towards said coil upon energisation thereof, wherein said armature is formed as a plane plate, and comprising rolling members between said coil and said armature, said armature being located opposite the spaced poles of said magnet at a distance less than the spacing of said poles, means including surfaces oblique to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translatory movement.

5. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising three balls between said coil and said armature, means including surfaces oblique to the attraction movement of said armature and in contact with said balls, said armature sliding in a non-rotary translatory movement on said balls on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translatory movement.

6. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising three balls between a groove in said armature and a groove in a member secured to said coil, said grooves being located obliquely to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translatory movement.

7. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising three balls between a groove in said armature and a groove in a member secured to said coil, said grooves being located obliquely to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translatory movement, said member secured to said coil being located outside the lines of magnetic flux between said armature and said coil.

with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translator-y movement outwardly away from said coil, and spring means acting obliquely relative to the direction of attraction of said armature, to urge said armature inwardly towards said coil to restore said armature to its initial position and to maintain said armature on said rolling members.

9. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising rolling members between said coil and said armature, means within said energising coil including surfaces oblique to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the attraction movement of said armature is converted into a non-rotary translatory movement.

10. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising balls located between grooves in said armature and a member secured to said coil, said slots having obliquely extending edges and being located obliquely to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a non-rotary translatory movement on said rolling members on energisation of said coil whereby the armature carries out simultaneously an attraction movement towards said coil and a rectilinear movement at right angles to said attraction movement upon energisation of said coil.

11. An electromagnet having an energising coil and an armature movable towards said coil upon energisation thereof, comprising rolling members between said coil and said armature, means including surfaces oblique to the attraction movement of said armature and in contact with said rolling members, said armature sliding in a n0n-rotary translatory movement on said rolling members on energisation of said coil whereby the armature carries out simultaneously an attraction movement towards said coil and a rectilinear movement at right angles to said attraction movement upon energisation of said coil, and leaf spring means acting obliquely relative to the direction of attraction of said armature, to restore said armature to its initial position and to maintain said armature on said rolling members.

References Cited in the file of this patent UNITED STATES PATENTS 1,158,991 Dixon et a1. Nov. 2, 1915 1,199,046 Bliss Sept. 26, 1916 1,293,052 Dinsmoor Feb. 4, 1919 2,449,178 Sansbury Sept. 14, 1948 2,496,880 Leland Feb. 7, 1950 

